Dear Members,
I am not the Administrator of the OurMedia list, but you don't need to 
send these requests to the whole listserv. There is a simple and more 
discrete way to do it by ourselves.
--> go to webpage of the list at 
https://lists.ou.edu/cgi-bin/wa?A0=OURMEDIA-L
--> among the 'Options' click on 'Join or Leave OURMEDIA-L'
--> input your name and E-mail address
--> click on 'Leave OURMEDIA-L'
--> confirm your decision in the automatic e-mail message that will be 
sent to you.

Hope this helps!

Best Regards,

Salvo